Safety brake system

ABSTRACT

A safety brake system for a vehicle, which automatically applies the brakes when the driver of the vehicle leaves his seat. The system includes an accumulator for accumulating a quantity of fluid under pressure from the master cylinder assembly of the vehicle when the brake pedal of the vehicle is applied. A valve is actuated when the driver leaves his seat to cause the accumulated fluid to flow to the brakes and apply same.

finite States Patent Smith [45] Ar. 4, 1972 [54] SAFETY BRAKE SYSTEM[56] References Cited [72] Inventor: William Van Smith, 1617 Duke Road,UNITED T TE PATENTS Memphlsi Tenn 38108 3,137,369 6/1964 Stromberg..303/1 8 x [22] Filed: Dec. 18, 1970 Primary Examiner-Edward A. SrokaPP 99,532 Assistant Examiner-H. S. Lane Attorney-John R. Walker, lllRelated U.S. Application Data [63] Continuation-impart of Ser. No.17,812, June 23, [571 v ABSTRACT 1969- A safety brake system for avehicle, which automatically applies the brakes when the driver of thevehicle leaves his seat. [52] U.S. CL ..303/19 The system includes anaccumulator for accumulating a quan- [51] Int. Cl. ..B60t 7/14 tity offluid under pressure from the master cylinder assembly 53 n w f Search303/13 19 of the vehicle when the brake pedal of the vehicle is applied.A

valve is actuated when the driver leaves his seat to cause theaccumulated fluid to flow to the brakes and apply same.

' 7 Claims, 3 Drawing Figures IOS lll l 113T SAFETY BRAKE SYSTEM CROSSREFERENCE TO RELATED APPLICATION This is a continuation-in-part of myco-pending application, Ser. No. 17,812, filed June 23, 1969, entitledSafety Brake System.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to safety brake systems for vehicles.

2. Description of the Prior Art Applicant has knowledge of the followingU.S. Pat. Nos. 1,956,978; 2,044,944; 2,750,010; 2,918,145; 3,259,203;3,280,933; 3,332,522; 3,360,305; 3,451,051; and 3,487,451.

The U.S. Pat. No. 1,956,978 shows a device for controlling the ignitioncircuit of a vehicle engine which has a delayed action for stopping theengine of a vehicle if the driver leaves his seat.

The U.S. Pat. No. 2,044,944 is used in conjunction with vacuum andcauses the brakes of the vehicle to be applied when the driver leaveshis seat.

The U.S. Pat. No. 2,750,010 has a mechanically actuated device whichautomatically operates to apply the brakes when the operator of the carleaves his seat.

The U.S. Pat. No. 2,918,145 discloses a brake band which is mechanicallyactuated whenever the operator leaves his seat.

The U.S. Pat. No. 3,259,203 discloses a seat actuated vehicle brakemechanism which utilizes spring means to actuate the brake.

U.S. Pat. No. 3,280,933 discloses a brake assembly which is spring setin the absence of an operator on the seat, and the weight of theoperator on the seat overcomes the spring force which tends to engagethe brake assembly, resulting in brake release. U.S. Pat. No. 3,332,522shows a vehicle operator seat brake control system wherein there isprovided a hydraulic motor which is spring-biased to apply the vehicleparking brake and when supplied with pressurized fluid releases thevehicle parking brake.

U.S. Pat. No. 3,360,305 discloses a dead man seat brake which includes atension spring that causes the seat to be moved upwardly and a lever tobe pivoted to cause a hydraulic actuator to expel fluid and cause thebrakes to be applied.

The U.S. Pat. No. 3,451,051 shows a fluid level indicator for masterbrake cylinders.

The U.S. Pat. No. 3,487,451 discloses a brake control system foroperating the brakes of a vehicle in response to actuation of anelectrical pressure switch in the drivers seat of the vehicle, which inturn controls a magnetic valve that causes the brakes to be applied byair, hydraulic fluid, vacuum or the like.

SUMMARY OF THE INVENTION The present invention is directed towardsproviding an improved and effective safety brake system for a vehiclewhich automatically applies the brakes when the driver leaves his seat.It is a concept of the present invention to provide an accumulator foraccumulating a quantity of fluid under pressure from the master cylinderassembly of the vehicle when the brake pedal is applied and by means ofa valve which is actuated by the driver leaving his seat, the fluid fromthe accumulator is caused to flow to the brakes for the actuationthereof. It is a further concept to provide means for disabling thedevice of the present invention if it is desired not to use the system,as for example, if the vehicle is in tow. Additionally, adjustment meansare provided to allow the operator of the vehicle to set the desiredbraking power.

The device of the present invention is relatively simple inconstruction, yet highly effective, and can easily be installed byinterposing the device in the hydraulic line of the existing brakingsystem.

The present invention includes an accumulator, valve means forselectively directing flow to the brakes of the vehicle from the mastercylinder assembly when in a first position and from the accumulator whenin a second position, and actuating means in the form of a cushion meansfor moving the valve means selectively into said first and secondpositions. The accumulator includes a cylinder, a piston slidablymounted in the cylinder and defining a chamber on one side of the pistonwith the piston being movable in a first direction to increase the sizeof the chamber and movable in the second and opposite direction from thefirst direction to decrease the size of the chamber, and spring meansurging the piston towards said second direction. The actuating means formoving the valve comprises a diaphragm means including a diaphragmchamber and a movable diaphragm member, a plunger attached to thediaphragm member and the valve means, and spring means urging thediaphragm and the plunger in the direction to move the valve means intothe above-mentioned second position. Cushion means including a cavitytherein for providing air under pressure when the driver of the vehicleis sitting thereon, and a line communicating the cavity with thediaphragm chamber whereby the air under pressure flows to the diaphragmchamber to move the diaphragm and the plunger in a direction to move thevalve means into said first position.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partially sectionalized andsomewhat schematic view of the safety brake system of the presentinvention.

FIG. 2 is a schematic view showing the valve of the system in a firstposition.

FIG. 3 is a view similar to FIG. 2 showing the valve in a secondposition.

DESCRIPTION OF THE PREFERRED EMBODIMENT The safety brake system 11 ofthe present invention comprises in general an accumulator 13, a valve15, and an actuator assembly 17 for actuating valve 15.

System 11 is adapted to be utilized in a vehicle of the type havinghydraulically actuated brakes, as for example, like the typical brakes19, each of which include the usual hydraulic ram 21, brake shoes 23, 25and back-off spring 27. In addition, the usual master cylinder assembly29 is provided that includes a piston 31. The usual brake pedal 33having a depending lever 35 fixedly attached thereto is pivotallymounted beneath the floorboard of the vehicle, not shown, for pivotabout a horizontal axis as at 37. The lower end of lever 35 is mountedin the usual manner to the piston rod 39 of master cylinder piston 31 asby the coupler 41. The usual spring 43 is attached to lever 35 and urgesthe brake pedal 33 upwardly. Thus, it will be understood that downwarddisplacement of the brake pedal 33 provides hydraulic fluid underpressure in the chamber 45 of master cylinder assembly 29.

Valve 15 is interposed in the usual conduit 47, which extends frommaster cylinder assembly 29 to rams 21 to divide the conduit 47 into afirst portion or conduit 47 extending between chamber 45 and valve 15and a second portion or conduit 47 which extends from valve 15 to rams21, it being understood that second conduit 47" is divided to flow tothe separate rams 21.

Accumulator 13 includes a cylinder 49 which is preferably disposedwithin a housing 51 that also encloses valve 15 and some of the othercomponents of system 11. In addition, accumulator 13 includes a piston53 slidably mounted in cylinder 49 to define an accumulator chamber 55in cylinder 49 on one side of piston 53, that is, that side of thepiston to the left as viewed in FIG. 1. Piston 53 is movable in a firstdirection (to the right as viewed in FIG. 1) to increase the size ofaccumulator chamber 55 and is movable in a second and opposite direction(to the left as viewed in FIG. 1) from said first direction to decreasethe size of accumulator chamber 55. Cylinder 49 is blocked off at itsends. Thus, on one end the cylinder is blocked ofi by suitable means asa portion of the housing 51 as at 57. The opposite end has an internallythreaded sleevelike member 59 which is fixedly received in the cylinder49 and has an externally threaded plug 61 received therein which bearsagainst a spring seat 63. A compression spring 65 extends between springseat 63 and piston 53 to urge piston 53 in said heretofore-mentionedsecond direction (to the left as viewed in FIG. 1).

A third conduit 67 extends between accumulator chamber 55 and firstconduit 47. A check valve 69 is interposed in third conduit 67 to permitflow from conduit 47' to accumulator chamber 55 through third conduit 67but to prevent flow in the opposite direction from accumulator chamber55 to first conduit 47'. A fourth conduit 71 is communicated at one endwith accumulator chamber 55 preferably through third conduit 67 and iscommunicated at the opposite end with valve 15. The connections ofconduit 71 and conduits 47 and 47" with valve are best seen in FIGS. 2and 3 wherein the valve 15 is shown schematically. It will be seen fromFIG. 2 that when the valve 15 is in said heretofore-mentioned firstposition, first conduit 47 is connected with second conduit 47" throughvalve 15, and fiow through valve 15 from fourth conduit 71 is blocked.From FIG. 3 it will be seen that when valve 15 is in saidheretofore-mentioned second position, flow is interrupted between firstconduit 47 and second conduit 47", and fourth conduit 71 is connected tosecond conduit 47" through valve 15.

Actuator assembly 17 includes a housing 73 removably mounted on housing51, a flexible and movable diaphragm 75 is mounted around the edgesthereof in housing 73 to define a diaphragm chamber 77 in the upperportion of housing 73 above diaphragm 75. A plunger 79 is fixedlyattached at the upper end thereof to the underside of diaphragm 75 andextends slidably downwardly through the bore 81 in an externallythreaded stud 83 that is fixedly attached in an opening 85 in housing51. The lower end of plunger 79 is fixedly attached to the movableportion 87 of valve 15. A spring seat in the form of a nut 89 isthreadedly engaged on stud 83. A compression spring 91 extends betweenspring seat 89 and the bottom side of diaphragm 75 to urge diaphragm 75and plunger 79 upwardly in a direction to urge valve 15 toward saidsecond position. Actuator assembly 17 additionally includes a flexibleand resilient hollow cushion 93 having a cavity 95 therein. Cushion 93is suitably placed on the set 97 of the vehicle, not shown, so that whenthe driver thereof is pressing thereagainst when seated, air underpressure is provided in cavity 95. It will be understood that, ifdesired, the cushion 93 may be placed on the forward surface of the backof seat 97 without departing from the spirit and scope of the presentinvention, in which case it will be understood that the pressure of thedrivers back against the cushion 93 will cause the heretoforementionedair under pressure in cavity 95. A line 99 communicates cavity 95 withdiaphragm chamber 77 whereby when the driver is in seat 97, the airunder pressure flows to diaphragm chamber 77 to move valve 15 into saidfirst position.

An assembly 101 is provided for releasably holding plunger 79 toreleasably hold valve 15 in said first position. Assembly 101 preferablyincludes a member 103 slidably mounted from housing 51 as by means ofthe bracket 105. Member 103 has a handle 107 attached thereto andextending upwardly therefrom through a slot 109 in housing 51. The innerend of member 103 is tapered as at 111 and adapted to engage a flange113 when the member 103 is moved to the right from the position shown inFIG. 1. When moved to the right by means of the handle 107, the taperedportion 111 engages the flange 113 and wedges it downwardly to holdvalve 15 in said first position to effectively inactivate system 11 sothat the brakes l9 operate in the normal manner. It will be understoodthat when it is desired to activate system 11 to its normal operatingcondition, the member 103 is moved to the left, as shown in FIG. 1.

In describing the operation of the system 11 and assuming that themember 103 is in the position shown in FIG. 1, and further assuming thatthe operator is sitting on the cushion 93, the air under pressure incavity 95 will be transmitted to diaphragm chamber 77 through theconduit 99 and will overcome the pressure of spring 91 so that themid-portion of the diaphragm 75 moves downwardly to cause valve 15 tomove into said first position. It will be understood that the amount ofpressure sufficient to overcome the pressure of spring 91 can beadjusted by moving the nut 89 so as to adjust for actuation by anydesired pressure or weight against cushion 93. Further, it will beunderstood that valve 15 will remain in said first position so long asthe person remains in the seat 97 and exerts pressure or weight on thecushion 93 sufficient to overcome the spring 91. With valve 15 in saidfirst position and with the operator in the seat 97 the brakes 19 willoperate in the usual manner, that is, when brake pedal 33 is depressed,piston 31 will move to the right and cause fluid flow through conduit 47to actuate the rams 21 and cause the brakes 19 to be applied. It willalso be understood that during normal operation of the system 11, theaccumulator 13 will become charged, that is, fluid will flow from firstconduit 47 through check valve 69, through third conduit 67 and intoaccumulator chamber 55 to move piston 53 to the right and compressspring 65. Then, subsequently when the driver leaves seat 97, spring 91will cause diaphragm 75 to move upwardly and move valve 15 into saidsecond position shown in FIG. 3, whereupon spring 65 will move piston 53to the left or in said second direction to cause fluid to flow throughfourth conduit 71 and second conduit 47" to the rams 21 and apply thebrakes.

Spring 65 will keep pressure on rams 21 until valve 15 is moved intosaid first position by the driver when he is again seated on seat 97. Itwill be understood that the plug 61 may be turned to increase ordecrease the tension on spring 65 so as to set the desired brakingpower.

Although the invention has been described and illustrated with respectto a preferred embodiment thereof, it is to be understood that it is notto be so limited since changes and modifications may be made thereinwhich are within the full intended scope of this invention.

I claim:

1. A safety brake system for a vehicle of the type having fluid actuatedwheel brakes and having a pedal-actuated master-cylinder assembly forproviding fluid under pressure when the pedal is displaced, said brakesystem comprising accumulator means for accumulating a quantity of fluidunder pressure from said master cylinder assembly when said pedal isdisplaced, means including valve means for selectively directing flow tosaid brakes from said master cylinder assembly when in a first positionand from said accumulator means when in a second position, and actuatingmeans for moving said valve means selectively into said first and secondpositions.

2. The safety brake system'of claim 1 in which said accumulator meansincludes a cylinder, a piston slidably mounted in said cylinder anddefining a chamber on one side of said piston and said piston beingmovable in a first direction to increase the size of said chamber andmovable in a second and opposite direction from said first direction todecrease the size of said chamber, and spring means urging said pistonin said second direction.

3. The safety brake system of claim 1 in which said actuating meanscomprises diaphragm means including a diaphragm chamber and a movablediaphragm member, a plunger attached to said diaphragm member adjacentone end thereof and attached to said valve means adjacent the oppositeend thereof, spring means urging said diaphragm and said plunger in adirection to move said valve means into said second position, cushionmeans including a cavity therein for providing air under pressure whenthe driver of the vehicle is pressing thereagainst, a line communicatingsaid cavity with said diaphragm chamber whereby when the driver of thevehicle is seated, the air under pressure flows to said diaphragmchamber to move said diaphragm and said plunger in a direction to movesaid valve means into said first position.

4. The safety brake system of claim 3 including means for releasablyholding said plunger to releasably hold said valve means in said firstposition.

5. A safety brake system for a vehicle of the type having fluid-actuatedwheel brakes and having a pedal-actuated master-cylinder assembly forproviding fluid under pressure when the pedal is displaced, said brakesystem comprising an accumulator cylinder, a piston slidably mounted insaid accumulator cylinder and defining an accumulator chamber on oneside of said piston and said piston being movable in a first directionto increase the size of said accumulator chamber and movable in a secondand opposite direction from said first direction to decrease the size ofsaid accumulator chamber, spring means urging said piston in said seconddirection, first conduit means communicated with said master cylinderassembly, a second conduit means communicated with said brakes, a thirdconduit means extending between said first conduit means and saidaccumulator chamber for conducting fluid flow from said first conduitmeans and said mastercylinder to said accumulator chamber to expand thesize of said accumulator chamber against the force of said spring meanswhen said pedal is displaced, a fourth conduit means communicated withsaid accumulator chamber; valve means, connected to said first, secondand fourth conduit means, for movement into a first position in whichflow is blocked from said fourth conduit means to said second conduitmeans and is directed from said first conduit means to said secondconduit means and into a second position in which flow is blocked fromsaid first conduit means to said second conduit means and fluid isdirected from said fourth conduit means to said second conduit means tocause said fluid under pressure from said accumulator chamber to flow tosaid brakes for the actuation thereof, and actuating means forselectively moving said valve means into said first and secondpositions.

6. The safety brake system of claim 5 in which said actuating meanscomprises diaphragm means including a diaphragm chamber and a movablediaphragm member, a plunger attached to said diaphragm member adjacentone end thereof and attached to said valve means adjacent the oppositeend thereof, spring means urging said diaphragm and said plunger in adirection to move said valve means into said second position, cushionmeans including a cavity therein for providing air under pressure whenthe driver of the vehicle is pressing thereagainst, a line communicatingsaid cavity with said diaphragm chamber whereby when the driver of thevehicle is seated, the air under pressure flows to said diaphragmchamber to move said diaphragm and said plunger in a direction to movesaid valve means into said first position.

7. The safety brake system of claim 6 including means for releasablyholding said plunger to releasably hold said valve means in said firstposition.

1. A safety brake system for a vehicle of the type having fluid actuatedwheel brakes and having a pedal-actuated master-cylinder assembly forproviding fluid under pressure when the pedal is displaced, said brakesystem comprising accumulator means for accumulating a quantity of fluidunder pressure from said master cylinder assembly when said pedal isdisplaced, means including valve means for selectively directing flow tosaid brakes from said master cylinder assembly when in a first positionand from said accumulator means when in a second position, and actuatingmeans for moving said valve means selectively into said first and secondpositions.
 2. The safety brake system of claim 1 in which saidaccumulator means includes a cylinder, a piston slidably mounted in saidcylinder and defining a chamber on one side of said piston and saidpiston being movable in a first direction to increase the size of saidchamber and movable in a second and opposite direction from said firstdirection to decrease the size of said chamber, and spring means urgingsaid piston in said second direction.
 3. The safety brake system ofclaim 1 in which said actuating means comprises diaphragm meansincluding a diaphragm chamber and a movable diaphragm member, a plungerattached to said diaphragm member adjacent one end thereof and attachedto said valve means adjacent the opposite end thereof, spring meansurging said diaphragm and said plunger in a direction to move said valvemeans into said second position, cushion means including a cavitytherein for providing air under pressure when the driver of the vehicleis pressing thereagainst, a line communicating said cavity with saiddiaphragm chamber whereby when the driver of the vehicle is seated, theair under pressure flows to said diaphragm chamber to move saiddiaphragm and said plunger in a direction to move said valve means intosaid first position.
 4. The safety brake system of claim 3 includingmeans for releasably holding said plunger to releasably hold said valvemeans in said first position.
 5. A safety brake system for a vehicle ofthe type having fluid-actuated wheel brakes and having a pedal-actuatedmaster-cylinder assembly for providing fluid under pressure when thepedal is displaced, said brake system comprising an accumulatorcylinder, a piston slidably mounted in said accumulator cylinder anddefining an accumulator chamber on one side of said piston and saidpiston being movable in a first direction to increase the size of saidaccumulator chamber and movable in a second and opposite direction fromsaid first direction to decrease the size of said accumulator chamber,spring means urging said piston in said second direction, first conduitmeans communicated with said master cylinder assembly, a second conduitmeans communicated with said brakes, a third conduit means extendingbetween said first conduit means and said accumulator chamber forconducting fluid flow from said first conduit means and saidmaster-cylinder to said accumulator chamber to expand the size of saidaccumulator chamber against the force of said spring means when saidpedal is displaced, a fourth conduit means communicated with saidaccumulator chamber; valve means, connected to said first, second andfourth conduit means, for movement into a first position in which flowis blocked from said fourth conduit means to said second conduit meansand is directed from said first conduit means to said second conduitmeans and into a second position in which flow is blocked from saidfirst conduit means to said second conduit means and fluid is directedfrom said fourth conduit means to said second conduit means to causesaid fluid under pressure from said accumulator chamber to flow to saidbrakes for the actuation thereof, and actuating means for selectivelymoving said valve means into said first and second positions.
 6. Thesafety brake system of claim 5 in which said actuating means comprisesdiaphragm means including a diaphragm chamber and a movable diaphragmmember, a plunger attached to said diaphragm member adjacent one endthereof and attached to said valve means adjacent the opposite endthereof, spring means urging said diaphragm and said plunger in adirection to move said valve means into said second position, cushionmeans including a cavity therein for providing air under pressure whenthe driver of the vehicle is pressing thereagainst, a line communicatingsaid cavity with said diaphragm chamber whereby when the driver of thevehicle is seated, the air under pressure flows to said diaphragmchamber to move said diaphragm and said plunger in a direction to movesaid valve means into said first position.
 7. The safety brake system ofclaim 6 including means for releasably holding said plunger toreleasably hold said valve means in said first position.